1. Field of the Invention
The invention in general relates to an apparatus for mounting a monitor to a rail of a railway track and, more particularly, to an apparatus which permits periodic adjustments in the position of the monitor relative to the rail head of a rail.
2. Description of the Prior Art
Such arrangements are well-known in the art and serve to position monitoring devices such as transducers or railway switches, and the like in as precise a position relative to the rail head of a rail as possible to ensure proper and flawless operation of the monitor. The rails, under the impact of traffic, are subject to considerable wear and tear resulting in a gradual lowering or disfiguring of the running surface of the rail head and, accordingly, periodic adjustments in the position of the monitor relative to the rail head is indicated. The monitors, as is well-known, serve to release signals in response to approaching wheels, and the signals are in turn utilized to actuate ancillary equipment such as warning lights or road crossing barriers and the like.
One arrangement of the kind under consideration is disclosed by European patent specification 0 342 526. Vertical movement of a monitor in accordance with that arrangement is accomplished by two vertically disposed adjustment bolts by means of which a mounting bracket may be moved relative to another mounting bracket. The adjustment bolts are provided with axial bores in which threaded bolts are seated for connecting the monitor to the brackets. In order to adjust the position of the monitor relative to the level of a rail head it is, therefore, necessary first to release bolts which maintain the relative position of the two brackets, thereafter to loosen the mounting bolts, and then to rotate the adjustment bolts for repositioning the monitor. Subsequent to the repositioning of the monitor the mounting bolts and the clamping bolts have to be tightened again.
Another arrangement is known from U.S. Pat. No. 4,753,403. The arrangement utilizes a lockable arrangement attached to the base of a rail for supporting a mounting bracket for a monitor. Each of two clamps is provided with a lug which serves to support the mounting bracket by means of a bolt threadedly received in the lug and extending through a vertical elongate slot in the bracket. Heightwise adjustment of the monitor requires loosening of the bolt in each lug and depends in no small measure upon the skill of the person attempting the heightwise adjustment by manually raising or lowering the monitor and maintaining its new position until the mounting bolts are again tightened.
Arrangements of the kind described in the prior art are disadvantageous in that they are either unduly complicated in their construction and utilization. Moreover, they may be subject to jamming during their heightwise repositioning.
It is, therefore, an object of the present invention to provide a mounting arrangement for a rail monitor which while structurally simple facilitates precise periodic adjustments in the position of the monitor relative to a rail.
It is a further object of the invention to provide a mounting arrangement for a monitor of the kind under consideration which includes a vertically disposed slide arrangement for accurately guiding the monitor during vertical movements necessary for its positional readjustments.
Yet another object of the invention resides in the provision of a positive vertical guide in the mounting arrangement of a monitor to prevent tilting or canting in directions parallel to the rail and possible jamming.